This section provides background information related to the present disclosure which is not necessarily prior art.
Radiation sensing, such as terahertz (THz) radiation sensing, can be applied in a variety of applications in industry, biology, and material science. Terahertz (THz) electromagnetic (EM) radiation waves fall on the electromagnetic spectrum between infrared radiation waves and microwaves, typically having a wavelength of greater than or equal to about 100 μm to less than or equal to about 1 mm with frequencies ranging from greater than or equal to about 0.1 THz to less than or equal to about 10 THz. THz radiation comprises a scientifically rich frequency band and offers unique value for imaging, chemical identification, and characterization of electronic and vibrational properties of materials. The low photon energies of THz radiation, e.g., 4 meV at 1 THz, are biologically safe, making it an attractive tool for non-ionizing radiation for imaging and treating biological tissues. Such non-destructive, non-radiation imaging is particularly desirable for medical imaging, chemical analysis, and security screening.
Thus, active and passive devices for THz radiation have been the subject of intense research. Most existing techniques for THz sensing either require bulky optics or need cryogenic cooling. Additionally, applications requiring fast detection in real time are limited due to long detector integration times (1-1000 ms). Development of small, rapid response, easy-to-operate THz components, including sources, waveguides, and detectors, would be highly advantageous. Indeed, better control and measurement of THz radiation is necessary to open up a range of potential uses and applications for THz radiation.